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Nature Communications Jan 2020Phase separation of substrates and effectors is proposed to enhance biological reaction rates and efficiency. Targeting protein for Xklp2 (TPX2) is an effector of...
Phase separation of substrates and effectors is proposed to enhance biological reaction rates and efficiency. Targeting protein for Xklp2 (TPX2) is an effector of branching microtubule nucleation in spindles and functions with the substrate tubulin by an unknown mechanism. Here we show that TPX2 phase separates into a co-condensate with tubulin, which mediates microtubule nucleation in vitro and in isolated cytosol. TPX2-tubulin co-condensation preferentially occurs on pre-existing microtubules, the site of branching microtubule nucleation, at the endogenous and physiologically relevant concentration of TPX2. Truncation and chimera versions of TPX2 suggest that TPX2-tubulin co-condensation enhances the efficiency of TPX2-mediated branching microtubule nucleation. Finally, the known inhibitor of TPX2, the importin-α/β heterodimer, regulates TPX2 condensation in vitro and, consequently, branching microtubule nucleation activity in isolated cytosol. Our study demonstrates how regulated phase separation can simultaneously enhance reaction efficiency and spatially coordinate microtubule nucleation, which may facilitate rapid and accurate spindle formation.
Topics: Animals; Cell Cycle Proteins; Cytosol; Karyopherins; Meiosis; Microtubule-Associated Proteins; Microtubule-Organizing Center; Microtubules; Ovum; Spindle Apparatus; Tubulin; Xenopus Proteins; Xenopus laevis
PubMed: 31937751
DOI: 10.1038/s41467-019-14087-0 -
Parasites & Vectors Jun 2020Gravid females assess the conditions of oviposition sites to secure the growth and survival of their offspring. Conspecific-occupied sites may signal suitable...
BACKGROUND
Gravid females assess the conditions of oviposition sites to secure the growth and survival of their offspring. Conspecific-occupied sites may signal suitable oviposition sites but may also impose risk due to competition or cannibalism at high population density or heterogeneous larval stage structure, respectively. Chemicals in the habitat, including chemicals emitted from other organisms, serve as cues for females to assess habitat conditions. Here, we investigated the attraction and oviposition preference of the Old World cutaneous leishmaniasis vector, Phlebotomus papatasi, to young and old conspecific stages, including eggs and evaluated the effect of a semiochemical associated with eggs and neonate larvae.
METHODS
Attraction and oviposition preference of Ph. papatasi to each of various life stages (eggs, first-, second-, third-, fourth-instar larvae, pupae and male and female adults) was investigated using cage and oviposition jar behavioral assays. Identification of organic chemical compounds extracted from eggs was performed using GC-MS and chemicals were tested in the same behavioral assays in a dose-response manner. Behavioral responses were statistically analyzed using logistic models.
RESULTS
Gravid Ph. papatasi females were significantly attracted to and preferred to oviposit on medium containing young life stages (eggs and first instars). This preference decreased towards older life stages. Dose effect of eggs indicated a hump-shaped response with respect to attraction but a concave-up pattern with respect to oviposition. Chemical analysis of semiochemicals from eggs and first-instar larvae revealed the presence of dodecanoic acid (DA) and isovaleric acid. Sand flies were attracted to and laid more eggs at the lowest DA dose tested followed by a negative dose-response.
CONCLUSIONS
Findings corroborated our hypothesis that gravid sand flies should prefer early colonized oviposition sites as indicators of site suitability but avoid sites containing older stages as indicators of potential competition. Findings also supported the predictions of our hump-shaped oviposition regulation (HSR) model, with attraction to conspecific eggs at low-medium densities and switching to repellence at high egg densities. This oviposition behavior is mediated by DA that was identified from surface extracts of both eggs and first-instar larvae. Isovaleric acid was also found in extracts of both stages.
Topics: Animals; Behavior, Animal; Female; Hemiterpenes; Larva; Lauric Acids; Male; Oviposition; Ovum; Pentanoic Acids; Pheromones; Phlebotomus; Pupa
PubMed: 32493498
DOI: 10.1186/s13071-020-04151-w -
Scientific Reports Nov 2021A complex interplay of biotic and abiotic factors underpins the distribution of species and operates across different levels of biological organization and life history...
A complex interplay of biotic and abiotic factors underpins the distribution of species and operates across different levels of biological organization and life history stages. Understanding ecosystem engineer reproductive traits is critical for comprehending and managing the biodiversity-rich habitats they create. Little is known about how the reproduction of the reef-forming worm, Sabellaria alveolata, varies across environmental gradients. By integrating broad-scale environmental data with in-situ physiological data in the form of biochemical traits, we identified and ranked the drivers of intraspecific reproductive trait variability (ITV). ITV was highest in locations with variable environmental conditions, subjected to fluctuating temperature and hydrodynamic conditions. Our trait selection pointed to poleward sites being the most physiologically stressful, with low numbers of irregularly shaped eggs suggesting potentially reduced reproductive success. Centre-range individuals allocated the most energy to reproduction, with the highest number of intermediate-sized eggs, whilst equatorward sites were the least physiologically stressful, thus confirming the warm-adapted nature of our model organism. Variation in total egg diameter and relative fecundity were influenced by a combination of environmental conditions, which changed depending on the trait and sampling period. An integrated approach involving biochemical and reproductive traits is essential for understanding macro-scale patterns in the face of anthropogenic-induced climate change across environmental and latitudinal gradients.
Topics: Adaptation, Physiological; Animals; Biodiversity; Climate Change; Ecosystem; Fertility; Ovum; Phenotype; Polychaeta; Reproduction
PubMed: 34837006
DOI: 10.1038/s41598-021-02351-7 -
Poultry Science Jan 2023Poultry production is linked with the use of veterinary medicinal products to manage diseases. Ionophore coccidiostats have been permitted for use as feed additives... (Review)
Review
Poultry production is linked with the use of veterinary medicinal products to manage diseases. Ionophore coccidiostats have been permitted for use as feed additives within the European Union (EU) for the prevention of coccidiosis in various species of poultry with except of laying hens. The presence of chemical residues in eggs is a matter of major concern for consumers' health. Despite such prohibition of use in laying hens, they were identified as the most common non-target poultry species being frequently exposed to these class of coccidiostats. Many factors can influence the presence of residues in eggs. Carryover of these class of coccidiostat feed additives in the feed of laying hens has been identified as the main reason of their occurrence in commercial poultry eggs. The physicochemical properties of individual compounds, the physiology of the laying hen, and the biology of egg formation are believed to govern the residue transfer rate and its distribution between the egg white and yolk compartments. This paper reviews the causes of occurrence of residues of ionophore coccidiostats in eggs within the EU with special emphasis on their disposition kinetics in laying hens, and residue transfer into eggs. Additional effort was made to highlight future modeling perspectives on the potential application of pharmacokinetic modeling in predicting drug residue transfer and its concentration in eggs.
Topics: Animals; Female; Coccidiostats; Chickens; Egg Yolk; Ionophores; Animal Feed; Ovum; Eggs
PubMed: 36410065
DOI: 10.1016/j.psj.2022.102280 -
Poultry Science Jun 2024In modern broilers, the period of embryonic development constitutes a greater proportion of a broiler's productive life. Hence, optimum embryonic development can exert a...
In modern broilers, the period of embryonic development constitutes a greater proportion of a broiler's productive life. Hence, optimum embryonic development can exert a significant influence not only on chick hatchability and hatchling quality but also on overall broiler growth and performance. Further healthy and active hatchlings are correlated with improved posthatch performance. In this regard, probiotics are good candidates to mediate early-life programming. Therefore, we evaluated the effect of In ovo probiotic spray application on broiler hatchability and hatchling quality. The experiment was set out as a completely randomized study with 2 independent trials. In each trial, 540 eggs (Ross 308) were either sprayed with phosphate buffered saline (PBS; control) or probiotics [∼9 log CFU/egg of Lactobacillus rhamnosus NRRL B-442(LR) or Lactobacillus paracasei DUP 13076 (LP)] during incubation. On day 18, eggs were transferred to the hatcher and set up for hatching. Starting on day 19, eggs were observed for hatching to determine the spread of hatch and hatchability. Hatched chicks were then assessed for quality using the Tona and Pasgar score and morphometric measurements including hatchling weight, yolk-free-body-mass and hatchling length were measured. Further, chicks were reared in floor pens for 3 wk to assess posthatch growth. Overall, In ovo probiotic supplementation improved hatchability and hatchling quality. Specifically, the spray application of LP improved hatchability by ∼ 5% without affecting the spread of hatch. Further, both LR and LP significantly improved Pasgar and Tona score, indicating an improvement in hatchling quality. Also, LP and LR significantly improved hatchling weight, yolk-free-body-mass, and posthatch growth in chicks. LR significantly improved hatchling weight and hatchling length (P < 0.05). Moreover, this increase in posthatch growth was positively correlated with hatchling weight in the probiotic groups. Overall, our study demonstrates that In ovo probiotic application exerts a positive effect on hatchability, hatchling quality, and subsequent posthatch growth.
Topics: Animals; Probiotics; Chickens; Lacticaseibacillus rhamnosus; Ovum; Lacticaseibacillus paracasei; Random Allocation; Chick Embryo
PubMed: 38552570
DOI: 10.1016/j.psj.2024.103624 -
Poultry Science Feb 2023The objective of this contribution was to summarize from scientific literature the optimal concentration of nonphytate phosphorus (NPP) in feed for laying hens. The... (Meta-Analysis)
Meta-Analysis
The objective of this contribution was to summarize from scientific literature the optimal concentration of nonphytate phosphorus (NPP) in feed for laying hens. The considered studies were one meta-analysis from 2012 and original studies published since then. Dietary treatments in the studies included variation in supplementation with mineral P sources and phytase. The studies investigated different periods of production and varied in duration but data were insufficient to analyze such factors in a systematic way. No study showed a positive effect on performance and eggshell when the NPP concentration was increased above 2.2 g NPP/kg of feed without the use of phytase. At such level, no consistent impairment of various bone quality traits were found but only few studies on bone quality traits were published. Overall, the data suggested that not more than 2.2 g NPP/kg of feed is needed for laying hens in different stages of production. This value can be reduced when phytase is added to the feed. Such reduction may differ depending on factors such as phytate content of the feed and phytase dosage. However, data are insufficient for calculating precise values of reduction. While phytate degradation in laying hens was markedly increased by phytase supplementation in several studies, effects of phytase supplementation on performance and bone traits in laying hens were less conclusive probably because the hens were supplied more than their NPP requirement. Transition to a system based on digestible P for laying hens similar to broiler chickens may support more precise P nutrition and more sustainable egg production in the future.
Topics: Animals; Female; Phosphorus; Chickens; 6-Phytase; Phytic Acid; Animal Feed; Ovum; Diet; Phosphorus, Dietary; Dietary Supplements
PubMed: 36476680
DOI: 10.1016/j.psj.2022.102344 -
Poultry Science Jun 2022This study investigated the effects of broiler chick hatching time and pull time on subsequent live performance. Hatching eggs were obtained from commercial broiler...
This study investigated the effects of broiler chick hatching time and pull time on subsequent live performance. Hatching eggs were obtained from commercial broiler breeder flocks of Ross 308 at 29 and 30 wk of age in trials 1 and 2, respectively. Eggs were incubated in 2 identical setters on 2 consecutive days. In both trials, portion of the eggs (9,600), incubated on the first day of set, were assigned to delayed-pull (DP) treatment, and the other portion of the eggs (9,600), incubated on the second day of set, were assigned to normal-pull (NP) treatment. The hatching period was divided into 3 hatching time groups, and chicks were classified as hatching in the early (478 to 490 h), middle (490 to 496 h), or late period (496 to 510 h of incubation). At 510 h of incubation based on the NP set date, all chicks were transferred to a broiler research house. A total of 7,200 and 8,400 chicks within 2 chick pull time treatments × 3 hatching time groups were raised in trials 1 and 2, respectively. The primary difference between the DP and NP treatments was an additional 24 h holding period in the hatcher for the DP group. Therefore, chick BW was higher at placement in the NP treatment than in the DP treatment (P < 0.001). However, this advantage disappeared by 7 d, and the average BW did not differ between the DP and NP treatments at 41 d. Chick pull time did not affect feed consumption or feed conversion ratio (FCR) at 41 d. Similar to pull time, hatching time did not impact BW, feed consumption or FCR at 41 d. However, for mortality and European Production Efficiency Index (EPEI) at 41 d, a hatching time × pull time interaction was observed (P < 0.001). Mortality was higher and EPEI was lower in late hatch chicks than in chicks hatched early and middle in the NP treatment, whereas for chicks in the DP treatment, mortality and EPEI did not differ among the hatching time groups. These data indicated that the DP treatment, which held the chicks for an additional 24 h in the hatcher under optimum conditions, produced a lower initial BW accompanied by a period of compensatory weight gain through 41 d, and no differences (P > 0.05) in live performance occurred due to the holding time in the hatcher. Overall, sending the late hatched chicks to the broiler house shortly after hatching increased their mortality and negatively affected their live performance (as measured by EPEI), unlike holding early hatched chicks for a relatively long time after hatching (50 h) in the hatcher.
Topics: Animals; Chickens; Ovum; Time Factors; Weight Gain
PubMed: 35468425
DOI: 10.1016/j.psj.2022.101845 -
Poultry Science Jun 2022Two hundred and twenty eggs from Transylvanian naked neck (TNN) chickens aged 30 wk were used to determine the effect of storage length on hatch window, chick quality,...
Two hundred and twenty eggs from Transylvanian naked neck (TNN) chickens aged 30 wk were used to determine the effect of storage length on hatch window, chick quality, and organ development. Forty-four eggs (11 eggs in 4 replicates) were stored in cold room (16±1.5°C) in batches for 0, 3, 6, 9, and 12 d before setting in incubator. Data collected were subjected to one-way analysis of variance. Hatchability of set and fertile eggs declined (P < 0.001) progressively as duration of storage increased, however, storage for 6 and 9 d differed not from each other. For 50% hatch, there was a decrease of 30 min/d in hatching time by 3 d-stored eggs before fresh eggs, while eggs stored for 6, 9, and 12 d had delay of 70, 65, and 30 min/d, respectively. Hatching commenced earlier (P < 0.01) in eggs stored for 0 and 3 d than in prolonged storage of eggs for 6 to 12 d. Eggs stored for 12 d recorded shorter (P < 0.001) hatch window than those stored for 0 to 9d. Significantly (P < 0.01) more eggs hatched per hour during hatch window in fresh eggs (3.9%/h) than other storage durations (1.70-2.12 %/h). Fresh and 6 d eggs hatched into heavier (P < 0.05) chicks (37.2 and 37.5 g, respectively) than 12d (32.7g). Chicks from 9 and 12 d storage were shorter in length than those for 0 to 6 d. Toe (P < 0.01) and shank+toe (P < 0.001) were longer in 0 d chicks than others. Activity and appearance were poorer (P < 0.01) in 12 d chicks than other groups. The quality of eye was better (P < 0.05) in 0 to 6 d chicks than 12 d group, however, 9 d chicks were similar to 12 d. Larger membrane remnant were found in 6 to 12 d chicks (P < 0.001) than in 0 d chicks, though not different from 3 d group. Navel of chicks from eggs stored for 0, 3, and 6 d were more closed than in 9 d, though not different from 12 d. Yolk remnant was larger in chicks of 3, 9, and 12 d storage length than in fresh and 6 d storage length. Tona score was higher in 0 to 6 d chicks than in 9 and 12 d chicks. There was no (P > 0.05) effect of egg storage length on chick yield and relative weight of chick organs. It could be concluded that in order to ensure good hatchability and quality chicks, TNN eggs could be stored for 3 d, but not beyond 6 d without intervention such as prewarming of long-stored eggs.
Topics: Animals; Chickens; Fertility; Incubators; Ovum
PubMed: 35381531
DOI: 10.1016/j.psj.2022.101834 -
Poultry Science Dec 2023The study aimed to analyze the hatching egg and physiochemical features of eggshells, thick albumen, amniotic fluid, and yolk during the incubation of Ross 308 chicken...
The study aimed to analyze the hatching egg and physiochemical features of eggshells, thick albumen, amniotic fluid, and yolk during the incubation of Ross 308 chicken eggs. Eggs (n = 755) were incubated for 21 d. Quality analysis of fresh eggs was performed. Eggshells, albumen, and yolk were collected from fresh eggs and incubation d 1, 7, and 14. Eggshell thickness and strength, pH, vitelline membrane strength, fatty acid (FA) in the yolk, pH, viscosity, lysozyme activity, and crude protein content in thick albumen and amniotic fluid were analyzed. Hatching parameters were calculated. Egg weight loss was constant (8.04% overall). Lower egg surface temperature was found on d 7 compared to d 4, 14, and 18. A lower thickness of posthatch eggshells was found. The strength of the vitelline membrane significantly decreased within 24 h (by over 58%). During incubation, there was a decrease in thick albumen/amniotic fluid pH; an opposite trend was found in yolk pH. The vitelline membrane strength was negatively correlated with the albumen pH. Lysozyme activity was higher in fresh thick albumen and up to 2 wk of incubation. On d 7, the lowest activity was found in the amniotic fluid. On d 14, lysozyme activity increased in amniotic fluid. The higher viscosity of the thick albumen was demonstrated on d 7 and 14 of incubation. The lowest viscosity in amniotic fluid was found on the same days. Crude protein content was higher in thick albumen (d 7 and 14) and lowest in amniotic fluid on d 7. The FA content changed between d 0 and 14. The results indicate different use of FA, where PUFA decreased. Eggshell is used in the last week of incubation. The thick albumen is reduced, while the biological value of amniotic fluid is increasing. Lysozyme activity, viscosity, and crude protein content may be interdependent. It may indicate the flow of substances and the transfer of functions from the thick albumen to the amniotic fluid during chicken embryogenesis.
Topics: Animals; Chickens; Egg Shell; Muramidase; Amniotic Fluid; Ovum; Albumins; Fatty Acids; Embryonic Development; Egg Yolk; Eggs
PubMed: 37832191
DOI: 10.1016/j.psj.2023.103119 -
Biology Letters May 2021Islands off southern Australia once harboured three subspecies of the mainland emu (), the smaller Tasmanian emu () and two dwarf emus, King Island emu () and Kangaroo...
Islands off southern Australia once harboured three subspecies of the mainland emu (), the smaller Tasmanian emu () and two dwarf emus, King Island emu () and Kangaroo Island emu (), which all became extinct rapidly after discovery by human settlers. Little was recorded about their life histories and only a few historical museum specimens exist, including a number of complete eggs from Tasmania and a unique egg from Kangaroo Island. Here, we present a detailed analysis of eggs of dwarf emus, including the first record of an almost complete specimen from King Island. Our results show that despite the reduction in size of all island emus, especially the King Island emu that averaged 44% smaller than mainland birds, the egg remained similar sized in linear measurements, but less in volume and mass, and seemingly had a slightly thinner eggshell. We provide possible reasons why these phenomena occurred.
Topics: Animals; Dromaiidae; Extinction, Biological; Islands; Ovum; South Australia
PubMed: 34034528
DOI: 10.1098/rsbl.2021.0012